Reporters photograph wanted posters of people facing criminal charges before a news conference in Washington, June 15, 2017, about the May 16, 2017, altercation outside the Turkish Embassy in Washington during the visit of the Turkish president. (VOA) -- Two Turkish-American men involved in a brawl at the Turkish Embassy earlier this year pleaded not guilty to assault charges in a Washington, D.C., courtroom Thursday.

Sinan Narin of Virginia and Eyup Yildirim of New Jersey faced charges of felony aggravated assault as well as making assault threats.

Court documents from Thursday indicate the men both entered pleas of not guilty and asked for a jury trial.

Eighteen people, many of whom were members of the Turkish ambassador's security detail, were indicted for allegedly attacking protesters outside the ambassador's residence on May 16. All 18 were charged with conspiracy to commit a crime of violence, a felony punishable by a maximum of 15 years in prison. Several faced additional charges of assault with a deadly weapon.

D.C. police have arrested four suspects with U.S. addresses, including including Narin and Yildirim; but warrants are still out for 14 Turkish security officers.

Another suspect -- Ayten Necmi of New York -- is due in court September 22, while the case of the fourth detainee, Jalal Kheirabaoi of Virginia, has been dismissed.

The brawl took place outside the residence of Turkey's ambassador to Washington shortly after U.S. President Donald Trump met with Turkish President Recep Tayyip Erdogan at the White House.

Video of the protest recorded by VOA's Turkish service shows what appear to be security guards and some Erdogan supporters attacking a small group of demonstrators.

Men in dark suits and others were recorded repeatedly kicking one woman as she was curled up on a sidewalk. Another wrenched a woman's neck and threw her to the ground. A man with a bullhorn was repeatedly kicked in the face.

After police officers struggled to protect the protesters and ordered the attackers to retreat, several suspects dodged the officers and continued the attacks.

The Turkish Embassy claimed that Erdogan's bodyguards were acting in "self-defense" during the incident, and that the protesters were affiliated with the Turkish left wing PKK or Kurdistan Workers' Party.